xref: /illumos-gate/usr/src/uts/common/fs/zfs/vdev_file.c (revision 8100c83b710504d354eb56493a5767659618f13b)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
24  */
25 
26 #include <sys/zfs_context.h>
27 #include <sys/spa.h>
28 #include <sys/spa_impl.h>
29 #include <sys/vdev_file.h>
30 #include <sys/vdev_impl.h>
31 #include <sys/zio.h>
32 #include <sys/fs/zfs.h>
33 #include <sys/fm/fs/zfs.h>
34 #include <sys/abd.h>
35 
36 /*
37  * Virtual device vector for files.
38  */
39 
40 static void
41 vdev_file_hold(vdev_t *vd)
42 {
43 	ASSERT(vd->vdev_path != NULL);
44 }
45 
46 static void
47 vdev_file_rele(vdev_t *vd)
48 {
49 	ASSERT(vd->vdev_path != NULL);
50 }
51 
52 static int
53 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
54     uint64_t *ashift)
55 {
56 	vdev_file_t *vf;
57 	vnode_t *vp;
58 	vattr_t vattr;
59 	int error;
60 
61 	/*
62 	 * We must have a pathname, and it must be absolute.
63 	 */
64 	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
65 		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
66 		return (SET_ERROR(EINVAL));
67 	}
68 
69 	/*
70 	 * Reopen the device if it's not currently open.  Otherwise,
71 	 * just update the physical size of the device.
72 	 */
73 	if (vd->vdev_tsd != NULL) {
74 		ASSERT(vd->vdev_reopening);
75 		vf = vd->vdev_tsd;
76 		goto skip_open;
77 	}
78 
79 	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
80 
81 	/*
82 	 * We always open the files from the root of the global zone, even if
83 	 * we're in a local zone.  If the user has gotten to this point, the
84 	 * administrator has already decided that the pool should be available
85 	 * to local zone users, so the underlying devices should be as well.
86 	 */
87 	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
88 	error = vn_openat(vd->vdev_path + 1, UIO_SYSSPACE,
89 	    spa_mode(vd->vdev_spa) | FOFFMAX, 0, &vp, 0, 0, rootdir, -1);
90 
91 	if (error) {
92 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
93 		return (error);
94 	}
95 
96 	vf->vf_vnode = vp;
97 
98 #ifdef _KERNEL
99 	/*
100 	 * Make sure it's a regular file.
101 	 */
102 	if (vp->v_type != VREG) {
103 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
104 		return (SET_ERROR(ENODEV));
105 	}
106 #endif
107 
108 skip_open:
109 	/*
110 	 * Determine the physical size of the file.
111 	 */
112 	vattr.va_mask = AT_SIZE;
113 	error = VOP_GETATTR(vf->vf_vnode, &vattr, 0, kcred, NULL);
114 	if (error) {
115 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
116 		return (error);
117 	}
118 
119 	*max_psize = *psize = vattr.va_size;
120 	*ashift = SPA_MINBLOCKSHIFT;
121 
122 	return (0);
123 }
124 
125 static void
126 vdev_file_close(vdev_t *vd)
127 {
128 	vdev_file_t *vf = vd->vdev_tsd;
129 
130 	if (vd->vdev_reopening || vf == NULL)
131 		return;
132 
133 	if (vf->vf_vnode != NULL) {
134 		(void) VOP_PUTPAGE(vf->vf_vnode, 0, 0, B_INVAL, kcred, NULL);
135 		(void) VOP_CLOSE(vf->vf_vnode, spa_mode(vd->vdev_spa), 1, 0,
136 		    kcred, NULL);
137 		VN_RELE(vf->vf_vnode);
138 	}
139 
140 	vd->vdev_delayed_close = B_FALSE;
141 	kmem_free(vf, sizeof (vdev_file_t));
142 	vd->vdev_tsd = NULL;
143 }
144 
145 /*
146  * Implements the interrupt side for file vdev types. This routine will be
147  * called when the I/O completes allowing us to transfer the I/O to the
148  * interrupt taskqs. For consistency, the code structure mimics disk vdev
149  * types.
150  */
151 static void
152 vdev_file_io_intr(buf_t *bp)
153 {
154 	vdev_buf_t *vb = (vdev_buf_t *)bp;
155 	zio_t *zio = vb->vb_io;
156 
157 	zio->io_error = (geterror(bp) != 0 ? EIO : 0);
158 	if (zio->io_error == 0 && bp->b_resid != 0)
159 		zio->io_error = SET_ERROR(ENOSPC);
160 
161 	if (zio->io_type == ZIO_TYPE_READ) {
162 		abd_return_buf_copy(zio->io_abd, bp->b_un.b_addr, zio->io_size);
163 	} else {
164 		abd_return_buf(zio->io_abd, bp->b_un.b_addr, zio->io_size);
165 	}
166 
167 	kmem_free(vb, sizeof (vdev_buf_t));
168 	zio_delay_interrupt(zio);
169 }
170 
171 static void
172 vdev_file_io_strategy(void *arg)
173 {
174 	buf_t *bp = arg;
175 	vnode_t *vp = bp->b_private;
176 	ssize_t resid;
177 	int error;
178 
179 	error = vn_rdwr((bp->b_flags & B_READ) ? UIO_READ : UIO_WRITE,
180 	    vp, bp->b_un.b_addr, bp->b_bcount, ldbtob(bp->b_lblkno),
181 	    UIO_SYSSPACE, 0, RLIM64_INFINITY, kcred, &resid);
182 
183 	if (error == 0) {
184 		bp->b_resid = resid;
185 		biodone(bp);
186 	} else {
187 		bioerror(bp, error);
188 		biodone(bp);
189 	}
190 }
191 
192 static void
193 vdev_file_io_start(zio_t *zio)
194 {
195 	vdev_t *vd = zio->io_vd;
196 	vdev_file_t *vf = vd->vdev_tsd;
197 	vdev_buf_t *vb;
198 	buf_t *bp;
199 
200 	if (zio->io_type == ZIO_TYPE_IOCTL) {
201 		/* XXPOLICY */
202 		if (!vdev_readable(vd)) {
203 			zio->io_error = SET_ERROR(ENXIO);
204 			zio_interrupt(zio);
205 			return;
206 		}
207 
208 		switch (zio->io_cmd) {
209 		case DKIOCFLUSHWRITECACHE:
210 			zio->io_error = VOP_FSYNC(vf->vf_vnode, FSYNC | FDSYNC,
211 			    kcred, NULL);
212 			break;
213 		default:
214 			zio->io_error = SET_ERROR(ENOTSUP);
215 		}
216 
217 		zio_execute(zio);
218 		return;
219 	}
220 
221 	ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE);
222 	zio->io_target_timestamp = zio_handle_io_delay(zio);
223 
224 	vb = kmem_alloc(sizeof (vdev_buf_t), KM_SLEEP);
225 
226 	vb->vb_io = zio;
227 	bp = &vb->vb_buf;
228 
229 	bioinit(bp);
230 	bp->b_flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
231 	bp->b_bcount = zio->io_size;
232 
233 	if (zio->io_type == ZIO_TYPE_READ) {
234 		bp->b_un.b_addr =
235 		    abd_borrow_buf(zio->io_abd, zio->io_size);
236 	} else {
237 		bp->b_un.b_addr =
238 		    abd_borrow_buf_copy(zio->io_abd, zio->io_size);
239 	}
240 
241 	bp->b_lblkno = lbtodb(zio->io_offset);
242 	bp->b_bufsize = zio->io_size;
243 	bp->b_private = vf->vf_vnode;
244 	bp->b_iodone = (int (*)())vdev_file_io_intr;
245 
246 	VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, bp,
247 	    TQ_SLEEP), !=, 0);
248 }
249 
250 /* ARGSUSED */
251 static void
252 vdev_file_io_done(zio_t *zio)
253 {
254 }
255 
256 vdev_ops_t vdev_file_ops = {
257 	vdev_file_open,
258 	vdev_file_close,
259 	vdev_default_asize,
260 	vdev_file_io_start,
261 	vdev_file_io_done,
262 	NULL,
263 	vdev_file_hold,
264 	vdev_file_rele,
265 	VDEV_TYPE_FILE,		/* name of this vdev type */
266 	B_TRUE			/* leaf vdev */
267 };
268 
269 /*
270  * From userland we access disks just like files.
271  */
272 #ifndef _KERNEL
273 
274 vdev_ops_t vdev_disk_ops = {
275 	vdev_file_open,
276 	vdev_file_close,
277 	vdev_default_asize,
278 	vdev_file_io_start,
279 	vdev_file_io_done,
280 	NULL,
281 	vdev_file_hold,
282 	vdev_file_rele,
283 	VDEV_TYPE_DISK,		/* name of this vdev type */
284 	B_TRUE			/* leaf vdev */
285 };
286 
287 #endif
288